Input To Reshape Is A Tensor With 2 * "batch_size" Values, But The Requested Shape Has "batch_size"

I want to make a RNN using a Keras sequential model with a tensorflow backend. When I implement the following code: batch_size = 8 batch_inputshape = (batch_size,x_train.shape[1],x

Solution 1:

EDIT : This code works for me, I have only changed the loss for simplicity.

import keras
from keras.layers import *
from keras.models import Sequential
from keras.objectives import *
import numpy as np

x_train = np.random.random((512,600, 103))
y_train = np.random.random((512,600,2))
batch_size = 8
batch_inputshape = (batch_size,x_train.shape[1],x_train.shape[2]) 
print(batch_inputshape) #(8, 600, 103)

model = Sequential()
model.add(LSTM(103,
           batch_input_shape = batch_inputshape,
           return_sequences = True,
          stateful = True))
model.add(Dropout(0.2))
model.add(LSTM(50,
           return_sequences = True,
          stateful = True))
model.add(Dropout(0.2))


model.add(TimeDistributed(Dense(10)))
model.add(TimeDistributed(Dense(2)))
model.add(Activation('softmax'))
model.compile(loss= "mse", optimizer='adam')

print (model.output_shape) #(8, 600, 2)

model.fit(x_train,y_train, batch_size = batch_size,
                       nb_epoch = 1, validation_split=0.25)

EDIT 2:

So the error was coming from the loss function. In the code you copied from github for ncce loss, they had outputs of shape (batch,10). You have outputs of shape (batch, 600, 2). So here is my edit of the function :

defw_categorical_crossentropy(y_true, y_pred, weights):
# https://github.com/fchollet/keras/issues/2115#issuecomment-274101310 #
    nb_cl = len(weights)
    # Create a mask with zeroes
    final_mask = K.zeros_like(y_pred[:,:,0])
    # get the maximum probability value for every output (shape = (batch,600,1))
    y_pred_max = K.max(y_pred, axis=2, keepdims=True)
    # Get the actual predictions for every output (shape = (batch,600,2))# This K.equal uses broadcasting, we compare two tensors of different sizes but it works (magic)
    y_pred_max_mat = K.equal(y_pred, y_pred_max)
    for c_p, c_t in product(range(nb_cl), range(nb_cl)):
        # Create the mask of weights to apply to the result of the cat_crossentropy
        final_mask += (weights[c_t, c_p] * K.cast(y_pred_max_mat[:,:, c_p], K.floatx()) * y_true[:,:, c_t])
    return K.categorical_crossentropy(y_pred, y_true) * final_mask

w_array = np.ones((2,2))
w_array[1, 0] = 100

As you can see, I just modified the index play because of your particular shape. The mask has to be of shape (batch, 600). The max has to be done on the 3rd dimension because there lie the probabilities that you want to output. The matrix multiplication to build the max needed to be updated too because of the shape of your tensors again.

This should work.

If you need more detailed explaination feel free to ask :-)